(n.) A state of being bent or curved; incurvation; a bending inwards.

aduncity apparent soundness aquilinity arching arcuation casuistry circling circuition circuitousness circuitry circulation circumambience circumambiency circumambulation circumflexion circumlocution circummigration circumnavigation concameration concavity convexity convolution crookedness curvation curvature curving curvity decurvation decurvature deviance deviancy deviation deviousness digression disingenuousness distortion equivocalness equivocation evasive reasoning excursion excursus excurvation excurvature fallaciousness fallacy gyre gyring hookedness incurvation incurvature incurvity indirection insincerity jesuitism jesuitry meandering misapplication mystification obfuscation obscurantism orbit orbiting oversubtlety perversion philosophism plausibility plausibleness rationalization recurvation recurvature recurvity rondure rotundity roundaboutness rounding sinuosity sinuousness sophism sophistical reasoning sophistication sophistry special pleading speciosity specious reasoning speciousness spiral spiraling subtlety tortuosity tortuousness turn turning vaulting vicious circle vicious reasoning wheeling